Victoria in June 2009

Based on preliminary data

This statement was prepared before all data for the period were available. This may affect some of the statistics presented.
Final values, which have had greater opportunity for data quality control, will be presented in the Monthly Weather Review, which is usually published during the fourth week of the month.

Note:

Note that Melbourne's rainfall total up to
30 June 2009 is 126.2 mm, the lowest total for the first half of the year on record
(previous record: 134.5 mm in January to
June 1967).

Nighttime temperatures were generally above the long-term normals during June in northern Victoria (by about half a degree Celsius). By contrast, in southern Victoria, nighttime temperatures were generally below the long-term normals by about half a degree.

Daytime temperatures were generally near to or slightly below the long-term normals during June in northern Victoria (by about half a degree Celsius). By contrast, in southern Victoria, daytime temperatures were generally above the long-term normals by about half a degree.

The relatively milder nights and cooler days in the north, were associated with slightly more cloud and rain than usual there, whilst the relatively cooler nights and milder days in the south, were associated with clearer skies and less rain than usual in that part of Victoria.

Synoptic Patterns:

The month was unusual in that it was characterised by a sequence of sub-antarctic anticyclones, which developed from time to time over eastern Australian longitudes. These systems tended to "block" progress of deep troughs in the westerlies as they approached our region, and resulted in a series of "cut-off" depressions moving across the SE of the country.

Notes

This statement has been prepared based on information available at
Noon on Wednesday 1 July 2009.
Some checks have been made on the data, but it is possible that results will change
as new information becomes available.

Averages are long-term means based on observations from
all available years of record, which vary widely from site to site.
They are not shown for sites with less than 10 years of record, as they cannot then be calculated reliably.
The median
is sometimes more representative than the
mean
of long-term average rain.

The Rank indicates how rainfall this time compares with the climate record for the site,
based on the
decile ranking
(very low rainfall is in decile 1, low in decile 2 or 3,
average in decile 4 to 7, high in decile 8 or 9
and very high is in decile 10).
The Fraction of average shows how much rain has fallen this time as a
percentage of the long-term mean.

Based on preliminary data

This statement was prepared before all data for the period were available. This may affect some of the statistics presented. In particular, maximum temperatures for the final day were not available, as the “accounting period” had not finished.
Final values, which have had greater opportunity for data quality control, will be presented in the Monthly Weather Review, which is usually published during the fourth week of the month.